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Altera_Forum's avatar
Altera_Forum
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14 years ago

D5M digital camera with DE2

Hi,

I am planning to implement a heart rate monitoring system using the DE2 board. I plan to implement the pulse oxymetry technology for which I would need a camera. I also plan to use the Nios II processor and from the documentation of the camera kit, it looks like it works well with DE2 and Nios processor.

I am new to these FPGA and hardware stuff but I am determined and have already got gew examples running on my fpga board with online help.

I want to know if my project is possible because pulse oximetry requires LED light as well. Thats what I have read.

Feedback wil be highly appreciated.

Thanks,

Vaibhav

7 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    I guess it is possible, why wouldnt be? What is ur question exactly?

  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    Hi aprado,

    Thanks for replying.

    This is what I got from a website:

    "The principle of pulse oximetry is based on the red and infrared light absorption characteristics of oxygenated and deoxygenated hemoglobin. Oxygenated hemoglobin absorbs more infrared light and allows more red light to pass through. Deoxygenated (or reduced) hemoglobin absorbs more red light and allows more infrared light to pass through. Red light is in the 600-750 nm wavelength light band. Infrared light is in the 850-1000 nm wavelength light band.

    Pulse oximetry uses a light emitter with red and infrared LEDs that shines through a reasonably translucent site with good blood flow. Typical adult/pediatric sites are the finger, toe, pinna (top) or lobe of the ear. Infant sites are the foot or palm of the hand and the big toe or thumb. Opposite the emitter is a photodetector that receives the light that passes through the measuring site."

    Here it says, you need a light emitter with red and infrared leds. How does the D5M camera provide me with these lights? Also, I don't know if the latest cell phones have capabilities to produce red and infrared light. There are apps available in both Android and iPhone to measure the heart rate using the pulse oximetry. These apps are pure software because from what I know, they use the existing camera on the phone and have no other hardware. How do they do it?

    Please visit the site instantheartrate dot com to see such an app on iPhone (Altera won't let me post links)

    Sorry if my questions sound naive.

    Thanks,

    Vaibhav
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    There are no LEDs on the D5M camera but you could always connect your own to the GPIO extension headers on DE2.

  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    Yes it would be something external to the D5M camera. You would need to use the GPIOs of your kit and buy some infrared modules, then you can do everything you want.

  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    Thank you for the response people.

    @Allen, you make it sound very easy to use the GPIOs. I am fairly new to the world of FPGAs and still playing around with the Nios processor on my DE2 board. I spent 5 days just getting my sdram running. Tried everything I read here on the forum. PLL's didn't work, Altera's sdram mega core function didn't work. Finally I found the Univerty IP Core called Clock Signals that did the trick for me. So I am determined to dive in this new world but it takes time for me.

    Regarding GPIOs and Infrared modules, do I have to do all the processing like using the ADC, DAC, etc? Also I wasn't able to find any good documentation on using the IrDa Core?

    Can you people point me in the right direction?

    Thanks a lot again. Appreciate your inputs.

    P.S: If I am not mistaken, Allen, you have some videos on YouTube, right, under the Terasic group? Thanks for those videos too.
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    Depending on your application, you might be able to use the LEDs directly, connecting them to the GPIOs (with a suitable resistor). You can do it two ways:

    1. using the i/o pin as a sink

    2. using i/o pin as a source.

    For the first option, use the VCC pin on the GPIOs as your source, and the sink should be the I/O pin. In this case, the LED would light if your I/O is low, and turn off when your I/O is high.

    The second option is just to use your I/O pin as the source with LED and resistor connected to ground.

    You can then control the brightness of the LED with a PWM signal.